Ore-flotation process.



H. c. & ETA. COLBURN.

one FLOTATION PROCESS.

APPLICATION FILED MAY 31. I916.

L fifimwu I Patented May15,1917.

2 SHEETS-SHEET \Q \Q WITNESSES INVENTORS JA! 2; h. C. COLBURN AND E. A.COL5UR/V 4 TTI) RA/ y I sociated.

v UNITED STATES PATENT OFFICE.

HERBERT G. GOIIBURN, F COIIORADO SPRINGS, AND ERNEST A. COLBURN', OFISENVEB,

COLORADO.

ortn-rno'rn'rroiv rnocnss.

Specification of Letters Patent.

application filed Hay81, 1 swam-1 0, REISSUED To all whom'a't ma zconcern: 1

Be it known that we, HERBERT C. CoLBURN and Banner A. COLBURN, citizensof the United States of "America, residing, respectively, at'ColoradoSrings, in the county of El Paso, State of olorado', and at Denver, inthe county of Denver and State of Colorado, have invented certain newand useful Improvements in Ore-Flotation Processes; of which thefollowing is .a specification.

Our invention relates to improvements in the ore concentration processcommonly known as the flotationrecess and its primary object resides inproviding a novel method of separating the valuable mineral particles infinely divided ores by the production of a froth in which said particlesare entrapped, exclusive of the gangue or worthless matter with whichthey were as- Our improved process consists in intermixing the finelydivided ore with a 'iquid and a substance having a selective afiinityfor the valuable particles and subjecting this mixture togetherwith airor other gas to violent agitation in a partial vacuum;

The vacuum expands the envelops of gas and colloidal matter which' arebroken up A by a constant bombardment of'the particles on the parts of amechanical agitator.

Thebared sulfids are immediately coated with oil and the solid particlesor the ore are thoroughly intermixed with the air and are in thiscondition discharged into a settling chamber in which. the j mixture 1sbrought to a comparative condition of rest under atmospheric pressure. j

bottom of the vessel and is 'drawn' as: The

air or other gas mixed'with the solids also rises to the surface in amultitude of small bubbles and congregates with the Oll into a heavytenacious froth in which the valuable mineral particles are entrapped.We are aware that apparatus have been devised in which oreepulp, oiland, air are intermixed by being drawn through a sue tion pump whichdelivers, the mixture into the settling chamber; and 1t sh uld. he unpartial vacuum and instead of being rapidly circulated through thechamber in which Patented Ma 15,1917.

the intermixture takes place, as'in the pumpmg system hereinbeforereferred to, it is.

retained in the mixing" chamber until a thorough intermixture of thematerials is obtained.-

Without limiting ourselves to the employment ofany particular apparatusfor effectmg the intermlxture of the materials, we prefer to use, byreason of thesimplicity of its construction, a chamber in which an agitating element has a rotary movement and which has an inlet of .atvmostone-fourth the area of its outlet. Y a 1 By the difference in sizesofthe ingress and egress openings, a partialvacuum is.

the chamber throughthe openings the flow constantly maintained in themixing chamher while the rotating element-impregnates the ore-pulp withoil and air admitted to through which may be controlled by automaticallyregulated valves.

The intake opening of the chamber connects with a supply of oresufficiently elevated to produce a head which feeds the 1 materialthrough the system in ratio to the discharge of the separatedsubstances; and the outlet opening of the chamber connectswith aspitzkasten which has an overflow for the froth and values in suspensionand an outlet for the settling less valuaible mat-.

ter.

If so desired, a number 'of mixing cham --bers and spitzkastens may beconnected ina series for the repeated treatment of settling Anembodiment of our invention fiasbeen illustrated in the accompanyingdrawings in" the various views of which llke parts are similarlydesignated and in wlzch,

r Figure 1 represents a sectional elevationof "a success1on= ofjumtsconstructed in accordance with our in ention and"-co perativelylcombined for therepeated treatment of the pulp,

, Fig. 2, an axial section through one of the mixing chambers showninFig. 1, taken along the line 22,

modified method of producing a partial.

vacuum in the mixing chamber.

Referring first to Fig. 1 of the drawings, 2 designates a spitzka'stenwhich has at its upper end an overflow 3 for the froth produced in theflotation process, and adjacent its bottom an outlet 4 for settlingmatter.

The reference numeral 5 designatesa mixing chamber provided with aninlet which by means of a conduit 6 is connectedwith an elevated sourceof ore supply 7, and with an outlet of comparatively large-diameterwhich connects with a conduit 8 extending into the spitzkasten for thedischarge of the material thereinto.

A rotary skimmer 9 mounted adjacent the overflow assists the movement ofthe supernatant froth into a laundry 10. v

In the construction shown in the drawings,

I a second mixing'chamber 12 and a second spitzkasten 13 are operativelyconnected with the first described devices for the repeated treatment ofthe matter discharged through the outlet 40f the first settling chamber.i

The outlet 4 is to this end connected with The material settlin in thelast-mentioned chamber is discharge through a valve-controlled outlet 16atthe bottom thereof.

In this connection wedesire it understood that a repeated treatment ofthe ore is re inlet opening 19.-

quired only under unusual circumstances .and that in most cases a singletreatment of the ore is suflici'ent to extract the values it contains.

practically all Thetwo spit'zkastens shown in Fig. 1 are connected by aconduit 17 for maintainin their liquid'contentson an even level.

Now, refe'rringto' Figs. 2 and 3' of the drawings, the mixing chamber 5is composed of a cylindrical casm 20 which has at its upper end atangent1ally disposed outletopening 18 and inone'of'its s desa centralThe last mentioned openin connects with a nozzle 21 the cross-.se'ctiona--area[o'f which is less than one-fourth the area of the outletopeningand to which is attached the conduit 6 shown in Fig. 1.

The nozzle has an opening 22 for the admission of air, and a secondopening 23 for the inlet of oil. The flow through the air opening iscontrolled by a valve- 24 which is yieldingly held upon its seat againstatmospheric pressure, by a spring 25'. t

The flow offoil through the opening 23 is controlled bya needle valve 26which opens and closes the outlet of a branch 27 which connects with aconveniently located source of oil supply, and the two valves areconnected for synchronous movement by means of a lever 28. v

It will be seen that in the operation, air is admitted past the valve 24while at the same time a proportionate quantity of oil is-introducedinto the material passing through the nozzle, through the opening 23. 1

The spring 25 is made of suflicient strength to maintain the vacuum inthe mixing chamber, constantly at a predetermined pressure.

The casing 20 has at its opposite sides, centrally disposed, axiallyalined stufiin'g boxes 29 through which passes a shaft 30 which impartsa rotary movementto the "mixing element within the chamber 5.

This element consists in the construction shown in Figs. 2 and 3, of amember 34 9 which is composed of a disk 31 fixed on the shaft adjacent aside of the chamber, and provided with a plurality of radially extendingvanes 32 which at their outer ends are connected by a circumferentialflange 33.

A second member 35 which in construction is identical to the beforedescribed member 34, is fixed in the casing against the opposite J sideof the chamber 5, and the two opposed members cooperate to thoroughlyintermix the materials introduced into the chamber, by a rapid rotarymotion of the one with relation to the other.

The device shown in Figs. 3 and 4, differs from the previously describedform, only in' the construction of the-cooperative members of the mixingelement.

Thev member mounted on the shaft 30 consists in this form of a disk 36and a series of radial vanes 37 which in their outer longitudinal edges,have recesses 38 to admit correspondingly "formed tongues 39 on thefixed at the opposite side of the chamunderstood.

The ore entering the mixing chamber through its inlet, is thoroughlyimpregnated with the oil and air entering the nozzle 21 through theopenings 22 and 23, in a partial vacuum resulting from the difference inthe areas of the inlet and outlet openings.

The partial vacuum in the mixing chamber expands the envelops of gas andcolloidal matter which are subsequently broken by contact with theblades of the mechanical mixer.

The consequently bared sulfid particles are immediately coated with oiland the solid constituents of the pulp including the gangue or worthlessmatter from which the sulfids are separated, are thoroughly intermixedwith the air or other gas which is and in which the coated sulfidparticles and" atomized air rise to the surface where they congregateinto a heavy tenacious froth, 'm which the values contained in the oreare entrapped.

The froth is removed from the surface of the material through theoverflow and the gangue or worthless matter settling in the bottom ofthe chamber is discharged through the outlet 16.

The settling material may be conveyed to the dump or conducted to asecond mixing chamber and a second spitzkasten as the circumstances andthe character of the ore may require.

In the construction' shown in Fig. 6, a mixing chamber 41 is (R nectedby means of a conduit 42 with a reservoir. 43 m which a vacuum ofdeterminate pressure is'maintained by a suction pump 44.

Themixing element in this form of our invention consists of a series ofpaddles 45 which radiate from a rotary vertical shaft 46. In theoperation of the modified form of our invention a partial vacuum ismain-.

tained in the reservoir 43 and the therewith communicating chamber 41 bythe action of the vacuum pump 44. f

The pulp, oil and airentering the chamber are thoroughly intermixed bythe rotary movement of the blades 45- on the shaft 46 it being observedthat as in the operation of the first-described apparatus, the aseousenvelops and colloidal matter are by the partial vacuum, and a fineintermixture of the different substances is obtained, which results in aproduct consisting of the sulfid particles of ore coated with oil, thegangue from which the coated particles are cleanly divided, and airwhich is thorou hly atomized throughout the finely divided mass, r

The advantages of our improved method of producing the froth in aflotation ore separating process, have been fully disroken up cussed inthe first'part of this descrlption,

and it is only necessary to add that by the automatic regulation of theair and oil supply", through the medium of the connected valves, theapparatus may be operated without requiri g the constant attention ofexpert operators and that by reason of the comminution of the ore andits thorough intermixture with the air and oil in a" ,finely dividedstate, any oil or grease which otherwise would be unsuited for thepurpose, may be emplo ed to produce a froth of the desired ten city.

Having thus described ur invention,

what we claim and de/SIIB to secure by Letters-Patent is: 1 ,1. Theprocess of separating valuable particles of finely divided ores,consisting in mixing ore-pulp with a substance having a selectiveafiinity/for the desired valuable particles, agitating andemulsifyingthe mixture with the addition of a gas, under a pressure less thanatmospheric, and then conducting the emulsified mixture to a sepa ratereceptacle in which the froth. can rise under a higher pressure.

2. The process of separating valuable particles of finely divided ores,consisting in mixing ore-pulp and oil, agitatin and emulsifying themixture with the a ditipn of a gas, under a pressurev less thanatmospheric, and then conducting the emulsified mixture to a separatereceptacle in which the froth can rise under a higher ressure.

In testimony whereof we have xed our signatures-in presence of twowltnesses.

HERBERT 'C. COLBURN. ERNEST A. COLBURN.

Witnesses:

= G. J. ROLLANDET,

L. Rnoanns.

